Electrodeposition of chromium



Patented Jan. 2, 1934 1,942,356 j OFFICE 1,942,356 ELEGTRODEPOSITION 0F CHROMIUM Colin G. Fink, New York, N. Y., and Charles H.

Eldridge, Detroit, Mich assignments, to United Chromium,

rated, New York, N. ware No Drawing. Refile for In po- Y., a corporation of Dela.-

abandoned application Serial No. 734,193, August 26, 1924. This application July 9, 1931,

Serial No. 549,800. Re

newed October 25, 1933 1 Claim. (01. 204-1) This invention relates to the electroplating of at first; and then the current is gradually brought chromium, and provides improvements therein. The baths and method 01' plating may be made up and practiced according to U. S. Letters Patent No. 1,581,188 to We have discovered that in certain instances the type of plate desired is most readily obtained by having the surface of the object to be plated in any suitable manliquid at the proper be accomplished ner, as by immersion in a temperature.

The bringing of the surface of the object to be plated to the temperature of the up to its proper value. Without this precaution, after interruption of the plating, the brightness of the surface will be lowered, becoming bluish-gray or gray in color.

This procedure permits chromium to be deposited over chromium, and minimizes the tendency for peeling and thereby resulting in good adherence.

By the use-of the invention, the obtaining of platings of uniform appearance is aided in those cases where by reason of temperature differences between the article and bath, the temperature at the surface of the article would be such as to affect the character of the deposit, and the invention hence increases the satisfaction and economy in the electroplating process.

This application is a renewal Serial No. 734,193, filed August 26, 1924.

What is claimed is:

In a process of electrodepositing chromium, bringing the object to be plated to the temperature of the bath prior to beginning the electrodeposition.

COLIN G. FIN'K. CHARLES H. ELDRIDGE.

of our application, I 

